Hi as any body had trouble with starter motor robbing all the power ,so bike won't fire up when spinning over ,but when you let the starter button off she back fires or odd time starts wondered if there was some kind of resistor???? Thanks A D

The T160 has a resistor in series with the coils (because they are 6 volt) like cars of the time. When the starter is used the relay bypasses the resistor to provide more power to the coils.If you have an analog Boyer, it will not work when the voltage gets down to 10 volts.

There is a charge pump circuit that keeps the voltage up on the Boyer. It is basically an oscillator (usually an lm555) that pulses into a capacitor at around 10KHz. I do not know if anyone makes these commercially. You might be able to wire a small LiPo battery in but you need a diode to isolate it from the main battery and another two to keep it from being over charged (one out and one in with a resistor).

Try starting it using the kick starter.If it starts easily then the ignition system is OK.Next use the electric leg--does the starter motor spin the engine over nice and quickly or does it struggle?Next you need to test the battery.Doesn't matter if it is a new battery----you need a good battery.Good and new do not always go together.Buy a battery load tester or take the battery to a garage or auto store--they will test it for you.If the battery tests good then you have to track down (no pun intended) where you are losing power in the system.The start point should be the kill switch then the ignition switch.HTH

Like TM says! a Deka YTX-20L has the POS post facing forward and out. My wife's T-160 button starts with a BB just fine. We did run a marine grade starter button wired direct to the solenoid with 10ga. wire. Don't use stock go button. Key on, hit remote button and sparklers lite. Minimum voltage drop. Look up the CCA of the Deka made in USA not a crap China battery.

Is the bike an old friend who's starter performance has diminished Or A new bike with unknown history ?

If the battery spins the starter well for a reasonable number of seconds ... this is a crude load test of the battery ... but not who is sharing the load .

The starter is a power hog ... small resistances in its wiring are magnified as voltage drop ...by the amount of current being drawn .

Check the voltage drop at the Boyer ... with just the ignition on and then with the starter engaged .... as mentioned above , the Boyer , especially if it's an older analog unit , needs arount 10 volts .

A good spring cleaning , or replacement of the starter ground strap... and perhaps the starter motor brushes might help ..

The starter is a power hog ... small resistances in its wiring are magnified as voltage drop ...by the amount of current being drawn .

Check the voltage drop at the Boyer ... with just the ignition on and then with the starter engaged .... as mentioned above , the Boyer , especially if it's an older analog unit , needs arount 10 volts .

..

You might also mention that an analog meter, (the ones with the needle), is the best kind to use to check the voltage drop when the starter is engaged.Digital meters take quick looks at the voltage and do not always see the lowest voltage when they display the reading. ie the voltage will jump around as it is going down on initial inrush, and read higher when the motor gets up to speed.Just a thought.

Some of the older Boyers will not work with the T160 electric start. Has something to do with static noise. John Healy posted a article about this years ago in the TIOC magazine.If you look at the Boyer pick up plate there is a lone resistor soldered and encapsulated in epoxy on the front. You have to replace that resistor with another one of a different value. And I don't remember what the value is.

The resistor used with the points ignition to momentarily energize the 6 volt coils with 12 volts during starting, must be removed from the electrical circuit!!!

The resistor in question on the pick-up plate should be 180 ohms (brown, grey, brown - with a gold band indicating it is a 5% accuracy). Earlier units had a different resistor.

If you have one of the newer pick-p plates missing third coil the are missing the coil should be facing the alternator. The earlier unit, with three coils, the coil adjacent to the alternator would pick-up RF and confuse the triggering circuit.

One thing that people fail to observe in this installation is the wires that served the points, two of which now serve the Boyer pick-up, runs into the wiring harness at the same point where the alternator wires do. They run parallel to each other. This allows the Boyer pick-up wires to pick-up RF from the alternator wires. The signal picked up from the alternator wires confuses the trigger unit in the control box and the bike will not start.

When diagnosing any electronic ignition one must pay close attention to Tridentman's: "You need a good battery, not a new battery!"

Electric starters produce a heavy load on the electrical system, especially the battery. Wire sizes, and the condition of all connections, will cause problems even with a good battery. This is especially true as the starter ages.

One must pay close attention to all of the connections in the circuit that feeds the electronic box. Starting at the battery, then the fuse holder, ignition switch, kill button and all of the electrical connectors must not be loose, be clean and have NOT gone high resistance. You can get a pretty good size voltage drop between the battery and the control unit even if you can read battery voltage at the feed wire attached to the unit. Because the Boyer, and other electronic units, turn off when there is no signal from the trigger plate, there is no load on the circuit. NO LOAD - NO VOLTAGE DROP. To actually measure the voltage drop you will have to create a load. You can do this by jumping the feed wire directly to the coil, thus creating a load (current draw). Then you can check to see if you have battery voltage at the point the feed wire is attached to the coil. On Triumphs of that era the kill button's two lead white connector inside the headlamp is one of the first places I start looking for a connection that has gone high resistance. Often you will find them turned brown, or black, from the heat generated by the resistance.

Might you have a wattage rating for that resistor. Thanks. Found the alternator output in watts. 120 watts @5000rpm. 75% of [email protected] 2400rpm. Using ohms law you can calculate the ratings for the proper resistor.

Years ago....before I saw the light and sold it for a T150V....in 1976 I bought a brand new stock standard T160V off the local dealer. The electric start would whirr away from day one but wouldn't start the bike. I had it 'repaired' under warranty twice, and it was still useless, might work OK sometimes if the motor was very warm. But never worked when cold. I had nil faith in it. I gave up on it. Kick start worked OK, as they always do. But a rebuilt one or one of DM's would be a different animal in the modern era.

After 2 years of ownership I sold it and then bought my T150V...which I still have. Funny thing is the dealer tried to get me to buy a T150V from the get go, but I thought I knew better. Pity cos the T160 was $2640 and the T150 was $1995 [750 Bonnie was $1795], so I could have saved myself some $$$.

Thanks guys for all your comments ,got it sorted , it was the Boyer box breaking down under load , Boyer said it possibly can't be that as it starts off the kick ?? But it was thanks again cheers Andy d

Hi Andy,I was getting a nasty kickback on my 1973 T150 until I got rid of the Boyer and put in a Trispark. It was giving me a hard kick back on the first try , then I could kick it over. Sincerely,Kara

Hi Andy,I was getting a nasty kickback on my 1973 T150 until I got rid of the Boyer and put in a Trispark. It was giving me a hard kick back on the first try , then I could kick it over. Sincerely,Kara

Typical Boyer. A friend of mine had one on his Commando. Had to replace several kick-start pawls before reverting to points. Could be that it just fires whenever it decides to turn on?